A public safety answering point (PSAP), sometimes called “public safety access point”, is a call center responsible for answering calls to an emergency telephone number for police, firefighting, and ambulance services. Trained emergency service call takers are typically responsible for obtaining relevant information from a caller and dispatching the appropriate emergency service resources to the appropriate location.
In order to assist the emergency call takers, many PSAPs utilize defined emergency service protocols (ESPs) for providing standard instructions for various types of common emergency service situations. For example, if a caller tells the call taker someone is not breathing, an appropriate ESP may guide the call taker through giving the caller instructions on performing CPR or other basic first aid procedures. Other protocols may be directed at how to obtain appropriate information from the caller. For example, if the call involves a bomb threat, an appropriate ESP may instruct the call taker to notify the bomb squad and fire department and give the call taker instructions on how to attempt to guide the conversation with the caller to obtain critical information. In conventional 9-1-1 systems, where the voice transmissions between a caller and call taker may be analog signals, and the call taker must know to recognize certain words or phrases spoken by a caller and look up any appropriate protocols. This additional step takes the call taker's attention away from dealing with the caller, and can cause delay and confusion which, in the context of an emergency services call, can lead directly to harm to individuals, damage to property, and/or additional, preventable consequences.
Advances in communication technology, specifically data connectivity and voice-over-IP technology, has led to the implementation of Enhanced-9-1-1 and Next Generation 9-1-1 standards. Broadly speaking, Next Generation 9-1-1 (“NG9-1-1”) can be viewed as a system comprised of Emergency Services IP networks (“ESInets”), internet protocol (“IP”) based software services and application, and various databases and data management processes that are all interconnected to a public safety answering point (PSAP). The NG9-1-1 system provides location-based routing to the appropriate emergency entity, such that a caller in need of help is automatically routed to the PSAP assigned to the caller's location. NG9-1-1 also provides standardized interfaces for call and message services, processes all types of emergency calls including non-voice (multimedia) messages, acquires and integrates additional data useful to call routing and handling for appropriate emergency entities. NG9-1-1 supports all legacy E9-1-1 features and functions and is intended to provide scalable solution for meeting current and emerging needs for emergency communication between callers and Public Safety entities.
The NG9-1-1 system architecture is defined by the National Emergency Number Association (“NENA”) i3 standard and supports end-to-end IP connectivity between a caller and a public safety answering point (PSAP). The i3 standard defines an ESInet, which sits between various, non-emergency communications networks and one or more PSAPs, as well as the ESInet's various functional elements, such as a Location Information Server (LIS) and Location Validation Function (LVF), the Emergency Services Routing Proxy (ESRP) and Policy Routing Function (PRF) and the Emergency Call Routing Function and Location to Service Translation (LoST) protocol. All of these elements are designed to provide robust and secure communications between a variety of communications devices and emergency service providers.
The i3 standard requires all calls presented to the ESInet from an originating network, such as a typical telecommunications service provider (“TSP”) network to use session initiation protocol (“SIP”) signaling to deliver the call and include the location with the call. SIP is a signaling protocol used to start, change and end telephone and multimedia communication sessions over IP networks. Upon reaching the ESInet, call traffic encounters the Border Control Function (BCF) which sits between external networks and the ESInet. An emergency service call, with location information, enters the ESInet through the BCF. After passing through the BCF, the first element inside the ESInet is the Emergency Services Routing Proxy (ESRP). The ESRP receives the call, and passes this information to an Emergency Call Routing Function (ECRF), which determines the next hop in routing a call to the requested service. The ECRF maps the call's location information and requested service (e.g. police, which may be routed to a city-operated PSAP or fire department, which may be routed to a county-operated PSAP) to an appropriate PSAP.
In the event an ESInet is provisioned in an area before the regional TSPs and other originating networks or PSAPs are NG9-1-1 capable, NENA has defined a transition model. In this case, the legacy E911 network has been replaced by the Emergency Services IP Network (ESInet) with all of the functional elements previously described, but on either end (originating network and/or PSAP) is a legacy environment. To provide connectivity to both the legacy networks and the legacy PSAPs, NG9-1-1 defines a legacy network gateway and a legacy PSAP gateway to convert the data to and from SIP messaging for transmission over the ESInet until such time as the originating networks and PSAPs become i3 capable.
A beneficial side effect of the transition to the NG9-1-1 environment is that all emergency service phone calls will be converted to digital data and stored for future review. This further enables new and advantageous information processing techniques to be applied to emergency service calls in real time in order to assist emergency service call takers in performing their jobs.